I have obtained a lovely 8 3/4 inch Verito in barrel but alas the aperture blades are completely missing. Is it feasible to cut a slot and use Waterhouse stops for a range of stops from F4 to F8 or should I just use the lens at F4 only? (I have a machinist friend who can bore a variety of hole sizes for me). I have another Verito 8 3/4 with aperture and find I use only stops F4 through F8 to get the diffusion I want.